/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.commons.beanutils;

import java.io.Serializable;
import java.lang.reflect.InvocationTargetException;

/**
 * <p>
 * Implementation of <code>DynaBean</code> that wraps a standard JavaBean instance, so that DynaBean APIs can be used to access its properties.
 * </p>
 * 
 * <p>
 * The most common use cases for this class involve wrapping an existing java bean. (This makes it different from the typical use cases for other
 * <code>DynaBean</code>'s.) For example:
 * </p>
 * <code><pre>
 *  Object aJavaBean = ...;
 *  ...
 *  DynaBean db = new WrapDynaBean(aJavaBean);
 *  ...
 * </pre></code>
 * 
 * <p>
 * <strong>IMPLEMENTATION NOTE</strong> - This implementation does not support the <code>contains()</code> and <code>remove()</code> methods.
 * </p>
 * 
 * @author Craig McClanahan
 * @version $Revision: 926529 $ $Date: 2010-03-23 11:44:24 +0000 (Tue, 23 Mar 2010) $
 */

public class WrapDynaBean implements DynaBean, Serializable {

    // ---------------------------------------------------------- Constructors

    /**
     * Construct a new <code>DynaBean</code> associated with the specified JavaBean instance.
     * 
     * @param instance
     *            JavaBean instance to be wrapped
     */
    public WrapDynaBean(Object instance) {

        super();
        this.instance = instance;
        this.dynaClass = (WrapDynaClass) getDynaClass();

    }

    // ---------------------------------------------------- Instance Variables

    /**
     * The <code>DynaClass</code> "base class" that this DynaBean is associated with.
     */
    protected transient WrapDynaClass dynaClass = null;

    /**
     * The JavaBean instance wrapped by this WrapDynaBean.
     */
    protected Object instance = null;

    // ------------------------------------------------------ DynaBean Methods

    /**
     * Does the specified mapped property contain a value for the specified key value?
     * 
     * @param name
     *            Name of the property to check
     * @param key
     *            Name of the key to check
     * @return <code>true<code> if the mapped property contains a value for
     * the specified key, otherwise <code>false</code>
     * 
     * @exception IllegalArgumentException
     *                if there is no property of the specified name
     */
    public boolean contains(String name, String key) {

        throw new UnsupportedOperationException("WrapDynaBean does not support contains()");

    }

    /**
     * Return the value of a simple property with the specified name.
     * 
     * @param name
     *            Name of the property whose value is to be retrieved
     * @return The property's value
     * 
     * @exception IllegalArgumentException
     *                if there is no property of the specified name
     */
    public Object get(String name) {

        Object value = null;
        try {
            value = PropertyUtils.getSimpleProperty(instance, name);
        } catch (InvocationTargetException ite) {
            Throwable cause = ite.getTargetException();
            throw new IllegalArgumentException("Error reading property '" + name + "' nested exception - " + cause);
        } catch (Throwable t) {
            throw new IllegalArgumentException("Error reading property '" + name + "', exception - " + t);
        }
        return (value);

    }

    /**
     * Return the value of an indexed property with the specified name.
     * 
     * @param name
     *            Name of the property whose value is to be retrieved
     * @param index
     *            Index of the value to be retrieved
     * @return The indexed property's value
     * 
     * @exception IllegalArgumentException
     *                if there is no property of the specified name
     * @exception IllegalArgumentException
     *                if the specified property exists, but is not indexed
     * @exception IndexOutOfBoundsException
     *                if the specified index is outside the range of the underlying property
     * @exception NullPointerException
     *                if no array or List has been initialized for this property
     */
    public Object get(String name, int index) {

        Object value = null;
        try {
            value = PropertyUtils.getIndexedProperty(instance, name, index);
        } catch (IndexOutOfBoundsException e) {
            throw e;
        } catch (InvocationTargetException ite) {
            Throwable cause = ite.getTargetException();
            throw new IllegalArgumentException("Error reading indexed property '" + name + "' nested exception - " + cause);
        } catch (Throwable t) {
            throw new IllegalArgumentException("Error reading indexed property '" + name + "', exception - " + t);
        }
        return (value);

    }

    /**
     * Return the value of a mapped property with the specified name, or <code>null</code> if there is no value for the specified key.
     * 
     * @param name
     *            Name of the property whose value is to be retrieved
     * @param key
     *            Key of the value to be retrieved
     * @return The mapped property's value
     * 
     * @exception IllegalArgumentException
     *                if there is no property of the specified name
     * @exception IllegalArgumentException
     *                if the specified property exists, but is not mapped
     */
    public Object get(String name, String key) {

        Object value = null;
        try {
            value = PropertyUtils.getMappedProperty(instance, name, key);
        } catch (InvocationTargetException ite) {
            Throwable cause = ite.getTargetException();
            throw new IllegalArgumentException("Error reading mapped property '" + name + "' nested exception - " + cause);
        } catch (Throwable t) {
            throw new IllegalArgumentException("Error reading mapped property '" + name + "', exception - " + t);
        }
        return (value);

    }

    /**
     * Return the <code>DynaClass</code> instance that describes the set of properties available for this DynaBean.
     * 
     * @return The associated DynaClass
     */
    public DynaClass getDynaClass() {

        if (dynaClass == null) {
            dynaClass = WrapDynaClass.createDynaClass(instance.getClass());
        }

        return (this.dynaClass);

    }

    /**
     * Remove any existing value for the specified key on the specified mapped property.
     * 
     * @param name
     *            Name of the property for which a value is to be removed
     * @param key
     *            Key of the value to be removed
     * 
     * @exception IllegalArgumentException
     *                if there is no property of the specified name
     */
    public void remove(String name, String key) {

        throw new UnsupportedOperationException("WrapDynaBean does not support remove()");

    }

    /**
     * Set the value of a simple property with the specified name.
     * 
     * @param name
     *            Name of the property whose value is to be set
     * @param value
     *            Value to which this property is to be set
     * 
     * @exception ConversionException
     *                if the specified value cannot be converted to the type required for this property
     * @exception IllegalArgumentException
     *                if there is no property of the specified name
     * @exception NullPointerException
     *                if an attempt is made to set a primitive property to null
     */
    public void set(String name, Object value) {

        try {
            PropertyUtils.setSimpleProperty(instance, name, value);
        } catch (InvocationTargetException ite) {
            Throwable cause = ite.getTargetException();
            throw new IllegalArgumentException("Error setting property '" + name + "' nested exception -" + cause);
        } catch (Throwable t) {
            throw new IllegalArgumentException("Error setting property '" + name + "', exception - " + t);
        }

    }

    /**
     * Set the value of an indexed property with the specified name.
     * 
     * @param name
     *            Name of the property whose value is to be set
     * @param index
     *            Index of the property to be set
     * @param value
     *            Value to which this property is to be set
     * 
     * @exception ConversionException
     *                if the specified value cannot be converted to the type required for this property
     * @exception IllegalArgumentException
     *                if there is no property of the specified name
     * @exception IllegalArgumentException
     *                if the specified property exists, but is not indexed
     * @exception IndexOutOfBoundsException
     *                if the specified index is outside the range of the underlying property
     */
    public void set(String name, int index, Object value) {

        try {
            PropertyUtils.setIndexedProperty(instance, name, index, value);
        } catch (IndexOutOfBoundsException e) {
            throw e;
        } catch (InvocationTargetException ite) {
            Throwable cause = ite.getTargetException();
            throw new IllegalArgumentException("Error setting indexed property '" + name + "' nested exception - " + cause);
        } catch (Throwable t) {
            throw new IllegalArgumentException("Error setting indexed property '" + name + "', exception - " + t);
        }

    }

    /**
     * Set the value of a mapped property with the specified name.
     * 
     * @param name
     *            Name of the property whose value is to be set
     * @param key
     *            Key of the property to be set
     * @param value
     *            Value to which this property is to be set
     * 
     * @exception ConversionException
     *                if the specified value cannot be converted to the type required for this property
     * @exception IllegalArgumentException
     *                if there is no property of the specified name
     * @exception IllegalArgumentException
     *                if the specified property exists, but is not mapped
     */
    public void set(String name, String key, Object value) {

        try {
            PropertyUtils.setMappedProperty(instance, name, key, value);
        } catch (InvocationTargetException ite) {
            Throwable cause = ite.getTargetException();
            throw new IllegalArgumentException("Error setting mapped property '" + name + "' nested exception - " + cause);
        } catch (Throwable t) {
            throw new IllegalArgumentException("Error setting mapped property '" + name + "', exception - " + t);
        }

    }

    /**
     * Gets the bean instance wrapped by this DynaBean. For most common use cases, this object should already be known and this method safely be
     * ignored. But some creators of frameworks using <code>DynaBean</code>'s may find this useful.
     * 
     * @return the java bean Object wrapped by this <code>DynaBean</code>
     */
    public Object getInstance() {
        return instance;
    }

    // ------------------------------------------------------ Protected Methods

    /**
     * Return the property descriptor for the specified property name.
     * 
     * @param name
     *            Name of the property for which to retrieve the descriptor
     * @return The descriptor for the specified property
     * 
     * @exception IllegalArgumentException
     *                if this is not a valid property name for our DynaClass
     */
    protected DynaProperty getDynaProperty(String name) {

        DynaProperty descriptor = getDynaClass().getDynaProperty(name);
        if (descriptor == null) {
            throw new IllegalArgumentException("Invalid property name '" + name + "'");
        }
        return (descriptor);

    }

}
